Serotonergic antidepressant drugs and L-dopa-induced dyskinesias in Parkinson's disease.

ABSTRACT

BACKGROUND: Serotonergic system is believed to play a role in levodopa-induced-dyskinesias pathogenesis, and serotonin transporter has been evaluated as potential target. AIM OF THE STUDY To retrospectively investigate the potential effect of selective serotonin reuptake inhibitors (SSRIs) during dopaminergic treatment, in the development of dyskinesias in patients with Parkinson's disease (PD). METHODS: One hundred and thirty-five consecutive patients with PD, with 10-year follow-up since diagnosis. Age at PD onset, duration of levodopa treatment, maximum daily dose, and SSRIs exposure were collected. Risk, latency, and severity of dyskinesias were evaluated comparing patients with and without SSRIs exposure. RESULTS: Forty-nine patients received SSRIs for a variable period, 86 were never treated; no significant difference between the groups was observed (P = 0.897) in the prevalence of dyskinesias. Considering latency between PD diagnosis and dyskinesias onset, patients exposed to SSRIs developed dyskinesias later (6.48 ± 1.99 vs 5.70 ± 1.89 years, P = 0.020). The median dyskinesia severity score was 0 in the exposed group vs 1 in non-exposed patients (P = 0.025). Multivariate analysis demonstrated SSRIs exposure as the only independent predictor, protecting from severe dyskinesia. CONCLUSIONS: Use of SSRIs in patients with PD did not protect from dyskinesias; however, exposure may delay the onset and reduce the severity, confirming modulation of the serotonergic system as possible antidyskinetic strategy.